Stitch-knitting or stitch-bonding machines are warp knitting machines by means of which basic materials or widths of basic materials, such as for example lays of thread, fleeces, textiles, warp-knitted fabrics, stitch-knitted fabrics and foils may be processed. For this purpose these machines have been provided over, between and under the rows of needles with a free space for passage of a basic material and the finished goods which extends the entire length of the rows of needles, so as to be able to feed the basic material undisturbed in the direction over the rows of needles and guide it through between the row of knitting needles and the row of guide needles, as well as to be able to remove the goods.
A machine of this kind has been disclosed wherein the drive means for the work tools, which include the drive means for the performance of the oscillatory motions of a guide bar provided with a row of guide needles, is located on a main shaft which is divided into a plurality of shaft parts separated from one another (DD 15,935 - C1. 52a, 9/04). As is shown in U.S. Pat. No. 3,354,672, which likewise concerns a stitch-bonding machine, a supplement of the said source patent DD 15,935 which was not represented in the DD patent, on a stitch-bonding machine an oscillating shaft, on which is supported at least one guide bar with a row of guide needles, hitherto was necessarily always driven at its two outer ends outside the space for passage of a basic material. (FIG. 1 of the U.S. patent relates only to the left end of the oscillating shaft). Drive of the oscillating shaft was effected by means of a coupling rod, which on the one hand is connected articulated with a connecting rod (a part of the drive means of the work tools) and, on the other hand forms a joint with a lever. The joint was attached transverse to the longitudinal axis of the oscillating shaft on the same. Since the connecting rod, which in this case is driven from a universal main shaft, is capable of moving to and fro, the oscillating shaft performs partial reversing turns which, through the compound needles, impart an oscillatory motion to the row of guide needles.
As an essential characteristic of stitch-bonding machines, the free space for passage of a basic material renders it necessary to drive the oscillating shaft only at its two outer ends outside the pass-through space, because the necessity of the pass-through space is linked with the condition that any arrangement of machine elements in the region of the pass-through space, as known in other warp knitting machines with, for example, means for supporting and operating guide bars, must be eliminated. Machine elements in the pass-through space would interfere with the feed of basic material. In other warp knitting machines the warp yarns to be fed may be guided around or carried past operating means for guide bars. However, the described drive of an oscillating shaft properly sized to the space available in the stitch-bonding machine exhibits troublesome shortcomings. When work is done at a high rate of oscillation, the distorsions occurring in the oscillating shaft assume such large orders of magnitude that, especially in the center region of the row of guide needles, the top and bottom terminal positions of oscillation of the guide needles are considerably further removed from the working plane of the compound needles than was theoretically predicted for satisfactory operation.
This then results in failures in the cooperation of the compound needles, the guide needles and the yarns to be processed, which mahy lead to a complete breakdown of operability of the warp knitting machine. The longer the oscillating shaft provided or the greater the working width of the machine selected, the more intensive the reciprocal distorsions that appear, which are followed by correspondingly severe operating failures. An increase in diameter or a non-circular cross section of the oscillating shaft either fails to eliminate above drawbacks or creates other serious disadvantages. For example, such a distinct increase in diameter of the oscillating shaft, including an appropriate bearing, which ensures normal cooperation of the compound needles and guide needles at high rates of oscillation and a great working width, results in such a space requirement that operation of the machine is significantly hindered.